Cell-mediated immunity in untreated and PUVA treated atopic dermatitis.

In 22 adult patients with atopic dermatitis, lymphocyte subpopulation counts, mitogenic responses to several PHA and Con A concentrations, nonspecific mitogen induced, and indomethacin sensitive suppressor cell functions and leukocyte migration inhibitory factor production were investigated. Patients with severe atopic dermatitis had normal PHA and Con A responses, although somewhat lower than matched controls, while mild AD patients equalled controls in this respect. No significant differences between AD patients and controls were detected with respect to lymphocyte subpopulations, suppressor cell function or leukocyte migration inhibitory factor production. Methoxalen plus ultraviolet light (PUVA) therapy induced significant clinical improvement in 9 out of 10 treated patients. A concomitant decrease of the mitogenic responses and increase of the Con A induced nonspecific suppressor cell activity was recorded, while other immunological parameters remained unaffected by the therapy. Thus PUVA therapy induces both local clinical and systemic immunological manifestations. The possibility that the observed immunological changes would be operative in the PUVA induced healing process, however, seems unlikely, as the present study did not disclose any obvious relationship between immune parameters and severity of atopic dermatitis.

Cell-mediated immunity in Darier's disease: effect of systemic retinoid therapy.

In five patients with Darier's disease, lymphocyte subpopulations, lymphocyte responsiveness to phytohaemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM) and purified protein derivative of tuberculin (PPD), leukocyte migration inhibitory factor (LMIF) production and suppressor cell activities were studied before and during oral etretinate treatment. Pre-therapy investigations of cell-mediated immunity showed no severe immunological dysfunction, although high responses to supra-optimal Con A concentrations suggested abnormalities in immunoregulatory lymphocyte subpopulations. In addition, two patients showed enhanced LMIF production upon stimulation with Con A, PWM and PPD. Retinoid therapy decreased the number of peripheral blood total leukocytes, lymphocytes and T-cells, normalized the LMIF production, and decreased the lymphocyte responses to mitogens. Furthermore, the dose-response curve to Con A changed toward normal and the suppressor cell activity regulating Con A responses tended to increase.

Differential in vitro effects of etretinate and retinoic acid on the PHA and con A induced lymphocyte transformation, suppressor cell induction and leukocyte migration inhibitory factor (LMIF) production.

The in vitro influence of two retinoids, etretinate and retinoic acid, on the human lymphocyte transformation, on the induction of suppressor cells and on leukocyte migration inhibitory factor (LMIF) production were investigated. Nontoxic concentration of retinoic acid increased significantly the PHA response to suboptimal mitogen concentrations, but had no effect on the Con A response; it also abolished the PHA induced LMIF production. In corresponding assays etretinate was without effect. Etretinate augmented the PHA induced suppressor cell activity, while retinoic acid was ineffective. No effect was observed on Con A induced suppressor cells by either retinoid. The findings extend the information about the immunomodulatory effects of retinoids and demonstrate that retinoic acid and etretinate have different effects on PHA and Con A induced immune responses. The mode of action of retinoids is discussed.

PUVA treatment in chromium hypersensitivity: effect on skin reactivity and lymphocyte functions.

Two male patients with longstanding contact sensitivity to chromium were treated with PUVA. One patient, suffering from concomitant photosensitivity, reacted very favorably; his skin lesions cleared and light tolerance increased. This was paralleled by a decrease in the photopatch test reactivity and by the extinction of the patch-test reactivity on PUVA-exposed (pigmented) skin. Patch and photopatch tests on PUVA-shielded skin showed no decrease in skin test reactivity. PUVA-treatment caused a decrease in the number of rosette-forming T cells and an increase in lymphocyte stimulation in both patients. In one patient, abnormally high PHA-induced suppressor cell activities were recorded prior to treatment; after PUVA therapy the values were back to normal. In both patients, the PPD-induced suppressor cell activity of PWN response was clearly increased by PUVA-therapy. Other suppressor cell functions were not much affected. It is concluded that while PUVA-therapy may produce some systemic immunological effects, its abating effect on contact sensitivity and photosensitivity is mainly mediated through local mechanisms in the skin.